A problem encountered in a typical home having a small child or small children therein is that the child perceives the telephone set as a toy and plays with the telephone thus disrupting service to the remaining telephones on the subscriber loop. Even when the child progresses past the "playing" stage, the child still tends to treat the telephone in an irresponsible manner. Thus, most parents do not even consider placing a telephone in a child's room until the child is mature enough to handle the responsibilities of a full feature telephone.
Small children generally do not possess the maturity necessary to handle the responsibility of dialing and most parents do not feel comfortable about their child dialing long distance or toll calls (e.g. 1-900-. . . ). In such cases a child's telephone should not allow the child to place long distance or toll calls without parental approval. Therefore, the ability to establish external communications should be conditional or nonexistent.
A child might forget to place the telephone back "on-hook" after use. Since it is possible to disable a subscriber loop by leaving it in an "off-hook" condition, the subscriber may not feel comfortable with allowing unsupervised access to a telephone which can establish and/or maintain the subscriber loop in an "off-hook" condition. Thus, the "off-hook" function should be conditional or nonexistent.
A ringing telephone might wake a napping child. Furthermore, if the "off-hook" function is not enabled on the conditionally operative telephone, then it would not possess the answer means. Thus, the ringer should be conditional or nonexistent.
If the conditionally operative telephone is to be used primarily by small children, then the handset should be smaller than a standard telephone to fit the child's head.
The present invention provides customized conditionally operative telephones used in conjunction with standard telephones to meet the needs of the end user (in the above example--a child) and to satisfy the concerns of the subscriber.
A standard telephone contains the following enumerated functional capabilities. The following list will hereinafter be referred to "the thirteen enumerated functional capabilities of a standard telephone".
1) "off-hook" function. The telephone company defines an "off-hook" status as the detection of a subscriber loop current above a certain predefined threshold. A standard telephone can place the subscriber loop into an "off-hook" status. This is typically done by completing the subscriber loop circuit through a sufficiently small impedance so as to allow a sufficiently large subscriber loop current. A typical telephone uses a switch hook to engage the "off-hook" status when the handset is lifted.
2) "on-hook" function. If the subscriber loop current is below the "off-hook" threshold current, then the telephone company identifies the subscriber loop as being in the "on-hook" status. The only action taken by the telephone company while the subscriber loop is in an "on-hook" condition is to send a ringing signal to indicate an incoming call. A typical telephone will open the subscriber loop circuit (except a small leakage current) when the handset is placed on the switch hook to provide the "on-hook" means.
3) Dialing function. In order to place a call, a telephone must provide the telephone company with a series of numbers to identify the telephone to be called. Each number is transmitted by either a make-break pulse sequence or a touch tone signal.
4) Ringing function. In order to indicate an incoming call, the telephone company will place a ringing signal on the subscriber loop. A typical telephone rings a bell or sounds a buzzer while the telephone is "on-hook" to indicate the presence of a ringer signal.
5) Sound transmission function. In order to communicate with other telephone users, a telephone must have the means to convert audible sound into electrical signals suitable for telephone system transmission. A microphone with associated amplifier circuitry typically is used to provide the sound transmission means.
6) Sound reception function. Conversion of suitable electrical signals from the subscriber loop into a speaker form a typical means of sound reception.
7) Dial tone indication function. When the telephone company desires to indicate to the subscriber loop that the telephone company is ready to receive a telephone number, the telephone company will place a dial tone signal on the subscriber loop. A typical telephone allows the sound reception means to provide the dial tone to the earpiece.
8) Status indication function. Audible signals are sent by the telephone company to indicate the status of a call (ringing, busy, . . . ). A typical telephone allows the sound reception means to provide the status indication signals to the earpiece.
9) Data generation and transmission function. Data is typically transmitted by the use of tones which are in the audible spectrum. Make-break pulse sequences may also be used for data transmission. Mechanical or electrical means may be provided for data generation and transmission. Use of a dialing means during a telephone conversation can provide the data generation and transmission function.
10) "hang-up" function. In order to terminate a telephone call, a user must place his subscriber loop in the "on-hook" status (i.e. hang up). Thus the "hang-up" means is normally equivalent to the "on-hook" means.
11) Answer function. In order to answer an incoming call, a user must place his subscriber loop in the "off-hook" status. Thus the answer means is normally equivalent to the "off-hook" means.
12) Call maintenance function. In order to maintain a telephone call the subscriber loop must remain in the "off-hook" condition. Thus the call maintenance means is typically equivalent to the "off-hook" means.
13) Data reception function. A standard telephone does not contain data reception equipment other than the sound reception means as described in (6).
Establishing a standard telephone as an apparatus which contains these thirteen enumerated functions as described herein, allows the framework to be defined from which a conditional operation telephone may be conceived. A standard telephone is designed to meet the needs of responsible adult users. Each conditional operation telephone will be designed to meet the needs of a certain class of telephone users as granted by the subscriber. Thus a subscriber can grant limited use of the telephone system under certain desired conditions to every class of telephone users.